An ounce—or one shot—of espresso has 63 milligrams (mg) of caffeine, according to nutritional information from the U.S. Department of Agriculture. By comparison, regular coffee averages 12-16 mg of caffeine per ounce.
So, yes, espresso technically has more caffeine, but in practice no one drinks just one ounce of coffee. You’re likely to have at least 8 ounces, which typically has 95 to 128 mg of caffeine.
However, caffeine counts for both espresso and coffee vary among brands and depend on the type of bean, the roast, the amount of coffee used, and the way it is prepared (brewed, French press, espresso machine, etc.) For example, at Starbucks, a shot of espresso has 75 mg of caffeine and an 8-ounce cup of its Pike Place medium roast coffee has 155 mg.From Consumer Reports.
A standard medium sized latte has two shots of expresso, which is about 126 mg of caffeine. So, regular coffee and expresso are actually about the same in typically consumed dosages.